NullPointerException when try save handlebars file

[ppasieka]

WebEssentials plugin throws exception when save file with extension *.handlebars

Below fragemnt from ActivityLog.xml

  <entry>
    <record>1082</record>
    <time>2016/06/18 05:52:56.036</time>
    <type>Error</type>
    <source>Editor or Editor Extension</source>
    <description>System.NullReferenceException: Object reference not set to an instance of an object.&#x000D;&#x000A;   at MadsKristensen.EditorExtensions.Compilers.EditorCompilerInvoker.Document_FileActionOccurred(Object sender, TextDocumentFileActionEventArgs e)&#x000D;&#x000A;   at Microsoft.VisualStudio.Text.Utilities.GuardedOperations.RaiseEvent[TArgs](Object sender, EventHandler`1 eventHandlers, TArgs args)</description>
  </entry>